Dallas has locked up home-court advantage in the first round of the playoffs but had dreams of catching San Antonio and the Lakers for one of the top two spots in the West. Those hopes likely went up in smoke when the Mavs closed a season-long six-game road trip with three straight losses, the last of which came in Portland on Sunday.
Gerald Wallace scored 19 points on 8-of-10 shooting and LaMarcus Aldridge netted 18 in that one as the Trail Blazers upended the Mavericks, 104-96, in a potential Western Conference playoff preview.
The Blazers, currently the No. 6 seed in the West, connected on 53 percent of their shots from the field to win going away against Dallas, which is third in conference standings.
Shawn Marion scored 19 points, Rodrigue Beaubois had 18 and Dirk Nowitzki added 16 for the Mavs, who finished their trip 3-3.
"I think the bottom line is we need consistency defensively," said Dallas head coach Rick Carlisle.
Dallas' loss in Portland, coupled with the Spurs' win over Phoenix the same day also clinched the Southwest Division title for San Antonio. The Mavs are two games behind the Lakers for the No. 2 seed with five games to play.
Denver, meanwhile, suffered a big loss of its own on Tuesday, falling to Northwest Division-rival Oklahoma City, 101-94, at the Pepsi Center. Kevin Durant scored 32 points and pulled down nine rebounds in that one as the Thunder inched closer to winning the Northwest.
Russell Westbrook added 18 points and six assists for the Thunder, who now hold a four-game lead over the Nuggets in the division. Oklahoma City holds the fourth spot in the Western Conference, while the Nuggets sit in fifth. Both teams have five games left in the regular season, including a meeting against each other in Oklahoma City on Friday.
Ty Lawson finished with 28 points for Denver, which secured a playoff spot with Sunday's win over the Lakers. Danilo Gallinari tallied 17 points and six boards.
"We beat ourselves tonight," Lawson said.
The Nuggets have won two straight and eight of their last 11 games versus the Mavs.